DESCRIPTION: The cost of using massive census and survey data in terms of dollars, time, technical skills, and substantive expertise usually limits use at the present time to a few well supported research centers. Hence the data are underutilized and many potential users are not benefiting from these public resources. Creation of an interactive hardware/software/data/instruction system, based on PDQ-Explore, that is capable of providing access, management, and analysis to a large number of users via the Internet can revolutionize research, education, and policy making. Public health, the social sciences, government, and industry can all benefit. The research conducted in this project will investigate methods of utilizing multiple processor systems and high performance disk subsystems in parallel applications to provide an innovative platform for supporting interactive access to massive data sets. The challenge is to incorporate new, off-the-shelf hardware into an information system that will provide researchers and the larger public with tools for cheap, fast, easy, and meaningful access to data.